step.unkeyed: Changing call with no idempotency key beside another changing call

Changing call with no idempotency key beside another changing call.

Area 12, Background work; not declinable; the next step is usually the agent's.

A changing call with no idempotency key is the only changing call in its action, so a receipt sent after a payment belongs in a subscriber of the payment's event:

example

use app { pay }use shared/providers/acme_pay/// Pays a supplier's invoice, then sends them a receipt.action pay_supplier(invoice: AcmePay.Reference) -> AcmePay.Payment {    var payment: AcmePay.Payment = pay.payments.create(        AcmePay.PaymentRequest {            reference: invoice        }    )    var receipt: AcmePay.Payment = pay.receipts.send(        AcmePay.PaymentRequest {            reference: payment.id        }    )    assert receipt.id == payment.id    return payment}

jadpo checkcheck failed: 1 error, 10 files

error pay.receipts.send takes no idempotency key, but pay_supplier makes another changing call, pay.payments.create

--> domains/bakery/actions/pay_supplier.jadpo:11:36

   |11 |     var receipt: AcmePay.Payment = pay.receipts.send(   |                                    ^^^^^^^^^^^^^^^^^ no key

reason: A changing call with no key may act twice if it is sent again, and once its answer is lost only an operator can say whether it went through, so it stays the only changing call in its action.
next: Move pay.receipts.send to a subscriber of an event pay_supplier emits (agent)
rule: step.unkeyed
help: https://jadpo.dev/docs/errors/step.unkeyed